Jamal Al Wadi from the Syrian city of Daraa speaks as Syrian opposition members listen after they announced a Syrian National Council in their bid to present a united front against President Bashar Assad’s regime, in Istanbul, Turkey, Thursday, Sept. 15, 2011. (no/Associated Press)

BEIRUT - A group of mostly exiled Syrian opposition figures on Thursday announced the formation of a Syrian National Council at a gathering in Istanbul, in the hope of presenting a viable alternative to the government of President Bashar al-Assad.

But it was unclear whether the 71 people named, drawn largely from the expatriate community but also from within Syria, would succeed in uniting the fractious assortment of street protesters, cyber activists, dissidents, Islamists and expatriate professionals who have emerged over the past six months to challenge the Assad regime.

The lack of a coherent plan to replace Assad has emerged as one of the biggest obstacles to the Syrian uprising, which marked its sixth month on Thursday without any sign that the government is likely to be dislodged soon.

In Washington and other Western capitals, officials complain that the absence of a united opposition movement raises concerns about what might happen if Assad were to fall, and tempers their efforts to support the revolt.

"One of the biggest things helping the [Syrian] government right now is this incredible disorganization of the opposition," said a Western diplomat in Damascus, who spoke on condition of anonymity in order to discuss sensitive subjects. "It's not only disorganized, there's a lack of vision. What's needed is a transition plan, to identify concrete steps" to replace Assad.

The council announced in Istanbul, which has been weeks in the making, appears to mark the most cohesive effort yet to come up with such a plan. Yaser Tabbara, a Chicago-based lawyer who is on the council, described it as an effort to "fill the vacuum that the international community has been waiting for for a while."

"We are going to put forward a credible, official voice of the revolution inside," he said.

But rival efforts to form similar councils in Doha, Cairo and other capitals have left many Syrian activists confused. Many members of the protest movement inside Syria were unaware that the Istanbul meeting was taking place.

"It seems like there's two councils each week," said Shakeeb al-Jabri, an activist in Beirut who has not yet decided which council to support. "I support any one of them that will get us out of this mess."

Many of the exiles living in the U.S. such as Washington based activists Radwan Ziadeh and Mohammed Abdullah, who recently met with Secretary of State Hillary Clinton, were on the new council list, as were many Islamists.

But the French academic Burhan Ghalioun, a secularist who is popular with youth activists inside Syria and who has been working to form a separate council was not included. Nor were any of the traditional Syrian opposition figures such as Michael Kilo and Arif Dalila, who are reportedly seeking to form their own group.

Tabbara said efforts were being made to reach out to other figures, and the council would likely expand as more join. "It's a work in progress," he said.